{
  "artifact_id": "qft.artifact.holography-quantum-gravity.wormholes-gravitational-path-integrals-and-ensembles.jt-double-trumpet-gluing-map",
  "title": "Disconnected Disks and JT Double-Trumpet Gluing",
  "kind": "topology-and-gluing schematic",
  "source_revision": 1,
  "source_date": "2026-08-29",
  "schematic": true,
  "not_to_scale": true,
  "reader_question": "For the same two asymptotic JT boundary data, what distinguishes the disconnected and connected contributions, and where does the double-trumpet gluing measure come from?",
  "takeaway": "The connected cylinder is a distinct topology obtained by gluing two trumpet exteriors along a geodesic seam and integrating its length and relative twist; connectedness alone does not establish an ensemble interpretation.",
  "scope": {
    "theory": "pure Euclidean Jackiw-Teitelboim gravity",
    "geometry": "connected, orientable, genus-zero surfaces with two labeled asymptotic boundaries, compared with two disconnected disks",
    "ads2_radius": "L_2 = 1",
    "schwarzian_coupling": "C > 0 and common to both asymptotic boundaries",
    "matter_insertions": "none",
    "status": "fixed-topology Euclidean benchmark; schematic geometry rather than a quantitative metric plot"
  },
  "symbols": [
    {
      "symbol": "beta_i",
      "meaning": "fixed inverse temperature, equivalently renormalized length data, on asymptotic boundary B_i",
      "integrated": false
    },
    {
      "symbol": "C",
      "meaning": "positive Schwarzian boundary coupling, with the same dimensions as beta_i",
      "integrated": false
    },
    {
      "symbol": "b",
      "meaning": "dimensionless length of the matched finite closed geodesic seam",
      "domain": "0 < b < infinity",
      "integrated": true
    },
    {
      "symbol": "theta",
      "meaning": "relative Fenchel-Nielsen twist around the matched seam",
      "identification": "theta is periodic with period b",
      "integrated": true
    },
    {
      "symbol": "S_0",
      "meaning": "JT topological coupling multiplying the Euler characteristic"
    }
  ],
  "panels": [
    {
      "id": "A",
      "title": "Same boundary contract, different topology",
      "fixed_boundary_data": [
        "B_1(beta_1)",
        "B_2(beta_2)",
        "common C > 0"
      ],
      "branches": [
        {
          "case": "disconnected",
          "topology": "D_1 disjoint union D_2",
          "connected": false,
          "components": 2,
          "total_euler_characteristic": 2,
          "euler_weight": "exp(2 S_0)",
          "amplitude_role": "product of two one-boundary disk contributions"
        },
        {
          "case": "connected",
          "topology": "M_(0,2), the cylinder or double trumpet",
          "connected": true,
          "components": 1,
          "euler_characteristic": 0,
          "euler_weight": "1",
          "amplitude_role": "connected two-boundary fixed-topology coefficient"
        }
      ],
      "comparison": {
        "euler_factor_ratio_connected_to_disconnected": "exp(-2 S_0)",
        "qualification": "This is only the ratio of topological Euler factors in the S_0 to infinity limit at fixed beta_i/C. The full amplitude ratio also contains beta-dependent boundary coefficients and any admitted fluctuation factors."
      }
    },
    {
      "id": "B",
      "title": "Cut, twist, and glue the connected cylinder",
      "objects": [
        {
          "object": "uncut double trumpet",
          "boundaries": [
            "asymptotic beta_1",
            "asymptotic beta_2"
          ],
          "distinguished_curve": "one matched closed geodesic seam of length b"
        },
        {
          "object": "left trumpet",
          "amplitude": "Z_T(beta_1,b)",
          "boundaries": [
            "asymptotic beta_1",
            "finite geodesic b"
          ]
        },
        {
          "object": "right trumpet",
          "amplitude": "Z_T(beta_2,b)",
          "boundaries": [
            "finite geodesic b",
            "asymptotic beta_2"
          ]
        }
      ],
      "relations": [
        {
          "from": "uncut double trumpet",
          "to": "left and right trumpets",
          "operation": "cut at the matched seam"
        },
        {
          "from": "left and right trumpets",
          "to": "uncut double trumpet",
          "operation": "identify equal-length seams, integrate one relative-twist period, and integrate b"
        }
      ],
      "twist_measure": "integral from 0 to infinity db times integral from 0 to b dtheta equals integral from 0 to infinity b db",
      "gluing_equation": "Zhat_(0,2)(beta_1,beta_2) = integral_0^infinity b db Z_T(beta_1,b) Z_T(beta_2,b)",
      "exception": "The cylinder is an integrated fixed-topology family, not one full JT saddle. It is exceptional: no ordinary stable Weil-Petersson core volume V_(0,2) is inserted."
    }
  ],
  "canonical_trumpet": {
    "equation": "Z_T(beta,b) = sqrt(C/(2 pi beta)) exp[-C b^2/(2 beta)]",
    "conditions": [
      "C > 0",
      "beta > 0",
      "b >= 0"
    ],
    "integrated_result": "Zhat_(0,2)(beta_1,beta_2) = sqrt(beta_1 beta_2)/(2 pi (beta_1 + beta_2))",
    "normalization_check": "C cancels from the integrated cylinder coefficient"
  },
  "admission_conditions": [
    {
      "condition": "connected topology is included in the declared topology sum",
      "failure": "excluding it makes the connected term zero by definition"
    },
    {
      "condition": "the declared integration cycle supplies a nonzero coefficient for the connected sector or relevant configuration family",
      "failure": "zero intersection leaves a formal geometry but no contribution"
    },
    {
      "condition": "zero modes, physical negative modes, ghosts, and normalization are consistently treated",
      "failure": "an unresolved unpaired physical negative mode blocks interpreting the displayed positive integral as the amplitude"
    }
  ],
  "claim_ceiling": {
    "licensed": "a connected contribution to the declared Euclidean gravitational path integral at the stated fixed-topology order",
    "not_licensed": [
      "a Lorentzian causal or traversable channel",
      "a convergent all-topology gravitational path integral",
      "an ensemble interpretation without an independently specified ensemble",
      "a violation of factorization in one exact fixed boundary theory"
    ]
  },
  "accessibility": {
    "reading_order": [
      "panel A shared boundary contract",
      "panel A disconnected branch",
      "panel A connected branch",
      "panel A Euler-factor comparison",
      "panel B uncut cylinder",
      "panel B cut and reverse gluing operations",
      "panel B two trumpet pieces and relative twist",
      "panel B measure and gluing equation",
      "panel B exceptional-cylinder and claim-boundary note"
    ],
    "non_color_encoding": "Disconnectedness is shown by two separate disk shapes; connectedness by one continuous cylinder; asymptotic boundaries use heavy solid strokes; matched seams use dashed strokes; cutting and gluing use distinct solid and dashed arrows; every object and relation is directly labeled.",
    "canvas": "explicit white background for light, dark, monochrome, and print contrast",
    "motion": "none"
  },
  "independent_checks": [
    "chi(D_1 disjoint union D_2) = 2 and chi(M_(0,2)) = 0, so the connected-to-disconnected Euler-factor ratio is exp(-2 S_0)",
    "one twist period theta in [0,b) gives integral dtheta db = b db",
    "multiplying the two canonical trumpet kernels and integrating b gives sqrt(beta_1 beta_2)/(2 pi (beta_1 + beta_2))",
    "the integrated result is symmetric under beta_1 exchange beta_2",
    "at beta_1 = beta_2 the integrated result is 1/(4 pi)",
    "the Schwarzian coupling C cancels from the integrated cylinder coefficient",
    "the stable-core formula is not applied to the exceptional pair (g,n) = (0,2)",
    "topology exclusion, zero contour intersection, and an unresolved unpaired negative mode are distinct failure modes",
    "no arrow or label represents Lorentzian propagation or ensemble averaging"
  ],
  "sources": [
    {
      "citation": "Saad, Shenker, and Stanford, JT Gravity as a Matrix Integral (2019), section 3.4.1, equations 133-138",
      "url": "https://arxiv.org/abs/1903.11115",
      "role": "canonical trumpet normalization, double-trumpet gluing measure, and integrated cylinder coefficient"
    },
    {
      "citation": "Mertens and Turiaci, Solvable Models of Quantum Black Holes: A Review on Jackiw-Teitelboim Gravity (2023), sections 4.2.1-4.2.2",
      "url": "https://doi.org/10.1007/s41114-023-00046-1",
      "role": "independent review of the exceptional disk and cylinder amplitudes and their normalization"
    }
  ]
}
